There have been some unexpected delays in the six months since crews broke ground on Route 4 in Farmington, but state Department of Transportation officials say it is a top priority to get the project completed on time.

Construction on a half-mile portion of the town's main thoroughfare, from Garden Street to Mountain Spring Road, started in April. The work is expected to continue through the summer of 2018.

John S. Dunham, district engineer for the DOT's fourth district, said the $12.6 million reconstruction is running about 53 days behind schedule, due to unforeseen issues with the water main in the area.

"Whenever you work in the ground and underneath the road, [there's] always some complications and difficulties that you can't always plan for because underground utilities aren't always exactly where you think they are when you plan the job," Dunham said.

"You don't have X-ray vision. You can't see in the ground."

Dunham said the DOT will be meeting with New Britain contractor Tilcon Construction, Inc. to discuss ways to make up time over the next year and a half.

Since April, crews have been clearing and excavating near the former Parson's Chevrolet dealership. Dunham said frequent travelers might not see much of a difference, because most of the ongoing work is underground, such as relocating utilities, creating a new water main, tying in water services to the buildings and installing major drainage fixtures.

"Once all that underground work gets done, then the contractor can come in and start building the roadway," he said. "I would think ... next spring or summer, you'll start to actually visually see some changes over there."

Once finished, there will be traffic lights at the intersection at High Street, a local road running parallel north of Route 4, and two eastbound lanes from the Route 10 intersection up to the I-84 on-ramp.

The town is exploring potential redevelopment concepts of a 40-acre area that Route 4 runs through. The area is adjacent to the Farmington Center historic district with the Farmington River to the west.

Dunham said most of the work will continue to take place Monday through Friday, 9 a.m. to 3 p.m., with some night work hours Monday through Friday, from 9 p.m. to 5 a.m.

There will be a nightly road closure and detour impacting the northern section of Route 10, at Waterville Road and the intersection of Route 4, from Oct. 24 to 28, from 9 a.m. to 5 a.m.

Detour signs will be posted. Farmington and Avon police will also direct traffic.

"We want to thank, certainly, everyone for their patience," Dunham said. "We know it's a very busy area through there. Building this job, we knew it was going to be difficult from a traffic standpoint and we really are doing our best to get the job done on time."